1. Field of the Invention
The present invention relates to a floor slab bridge structure formed by hammer-setting slab concrete between sides of respective bridge girders, which are aligned in a bridge width direction, in a length direction of the bridge girders and comprising a composite structure of the bridge girders and the slab concrete.
2. Description of Related Art
Conventional floor slab bridges adopt a flexible joining structure, in which bridge girders are supported on bridge bottom surfaces of concrete bridge piers through rubber bearings and expansion and contraction, deflection, or distortion of the bridge girders are absorbed by the rubber bearings.
However, such flexible joining structure involves a problem that there is a fear of bridge collapse due to a large earthquake, and rubber bearings suffer degradation in function due to age deterioration and are very expensive.
On the other hand, Patent Document 1 (JP-A-2000-319816) proposes, as a method of construction in place of the flexible joining structure with the rubber bearings, a method of construction in which bridge girders are supported on bridge bottom surfaces of concrete bridge piers through non-rubber bearing. Connection concrete is additionally deposited on the bridge bottom surfaces, and bridge girder portions are embedded in the connection concrete, to thereby form a rigid joining structure of the bridge girders and the individual bridge piers.
However, the method of construction, in which rigid joining is achieved through independent connection concrete additionally deposited on the individual concrete bridge piers, is not functionally effective to provide strength for expansion and contraction, distortion, etc. of bridge girders extending between bridge piers, and to ensure the strength of independent connection concrete itself for expansion and contraction, distortion, etc. of bridge girders. Therefore, with such independent connection concrete, stress concentration and cracks or the like are generated in the bridge girders and the independent connection concrete such that the structure does not effectively function as an earthquake resistant structure against a large earthquake.